Why join?

“It’ll help to stem the flow of refugees, to manage the human tragedy in better ways than we’ve able to do so far,” he said.

He declined to say whether the vessels would rescue migrants if they encountered a sinking boat.

But he said: “This isn’t about stopping or pushing back refugee boats … [We’ll] provide high-quality information to the coastguard of Turkey and the coastguard of Greece and the efforts of the European Union.”

He noted that Saceur, Nato's operational headquarters in Belgium, would instruct a "standing maritime group which is already in the region" to "move now … immediately".

The vessels, which are already in the eastern Mediterranean, consist of a German supply ship, FGS Bonn, which is in command of the operation, a Turkish frigate, TCG Barbaros, and a Canadian frigate, HMCS Fredericton.

Stoltenberg said he expected other Nato states to reinforce it “in the near future”.

He also said Nato surveillance planes would help to gather information about migrants on the Syria-Turkey land border.

The Aegean operation comes after Germany, Greece and Turkey made a surprise joint request earlier this week for Nato help.

But Stoltenberg noted that Turkish military assets would not operate in Greek maritime zones or in Greek airspace, amid the 40-year old Greek-Turkish dispute over northern Cyprus.

He said Nato would share its Aegean surveillance data with the EU’s border-control agency, Frontex, and with EU institutions more broadly.

But with the Cyprus dispute also clouding EU-Nato information exchange, the Nato chief noted that new protocols for the EU cooperation must first be put in place.

The request for Nato aid came after more than 1 million asylum seekers, most of them Syrians, came to the EU last year.

The EU had earlier asked Turkey to stop the migrants in return for €3 billion in aid and a more orderly “relocation” scheme to Europe.

But the EU still has not paid out any money and Turkey has rejected the relocation idea, while the number of people crossing from Turkey to the Greek islands is higher now than at the same time last year.

The EU launched its own naval operation last year, named Sophia, to stop people smugglers on the Libya-Italy maritime route.

But the vast majority of asylum seekers began coming via the Aegean route shortly after Sophia started work.

An EU source told EUobserver that Sophia has, in the past five months, mostly rescued migrants and brought them to EU shores instead of cracking down on smuggler groups.

"It's doing the opposite of what it was meant to do because it encourages more people to try to make the sea crossing," the source said.

Blocking Russia

Stoltenberg spoke after a meeting of Nato defence ministers, which also agreed to help the US-led anti-jihadist coalition in Syria and to post more troops to eastern Europe to deter Russian aggression.

He said so-called Awacs radar planes will help the US, which requested the Nato aid, to conduct more air strikes against Islamic State.

On Russia, he said Nato did not see any “imminent threat” that Russia would attack one of its easterly member states.

But he said its vast hike in military spending, holding of snap military drills in the Ukraine and Baltic Sea regions and its “willingness to use force to intimidate neighbours and to change borders in Europe” merit posting more troops to eastern Europe.

His comment on changing borders refers to Russia’s annexation of Crimea, a Ukrainian peninsula, two years ago.

Opinion

We must not undervalue what a massive step the European Parliament vote represents. The hard work has paid off. We can take a moment to celebrate, but the hard work begins again for finalising strong protection for European whistleblowers.